What's the first wrong statement in the proof below that $ \triangle CEB \cong \triangle DEB$ $ \; ?$ $ \overline{BC} $ is parallel to $ \overline{DF} $. This diagram is not drawn to scale. $A$ $B$ $C$ $D$ $E$ $F$ Givens $ \angle DBE \cong \angle CFE$ $, \ $ $ \overline{BE} \cong \overline{EF}$ $, \ $ $ \angle BED \cong \angle CEF$ $, \ $ $ \overline{BE} \cong \overline{AB}$ $, \ $ $ \angle BED \cong \angle BAC$ $, \ $ and $\ $ $ \angle BDE \cong \angle ACB$ Proof $ \triangle CEF \cong \triangle DEB$ because ASA $ \overline{CE} \cong \overline{DE}$ because corresponding parts of congruent triangles are congruent $ \angle BED \cong \angle CBE$ because alternate interior angles are equal $ \triangle CEF \cong \triangle CAB$ because AAS $ \angle ABC \cong \angle CFE$ because corresponding parts of congruent triangles are congruent $ \triangle CEB \cong \triangle DEB$ because SSS
Try going through the proof yourself: write down the givens, and then see if they justify the next step for the reason given. Then do the same thing for the next step, and the next, until you run into something that you can't justify, or you finish the proof. $ \triangle CAB \cong \triangle CEF$ is the first wrong statement.